Here’s a good example of when a reputable credit repair service can help you do something you may not be able to accomplish yourself. If you have a collection account that’s been sold to a few different debt collectors, it can appear on your credit report multiple times. That information is accurate but having that one debt dinging your credit score multiple times doesn't meet the “fair” standard that Padawer mentioned.
Either way, you should always remove any errors or outdated information from your credit report — regardless of the actual effect on your score — as soon as you discover them. A clean credit report can give you peace of mind the next time you apply for a loan; you’ll know that an inaccurate credit score isn’t holding you back from qualifying for a better interest rate, saving you time and money in the long run.
Opening several credit accounts in a short amount of time can appear risky to lenders and negatively impact your credit score. Before you take out a loan or open a new credit card account, consider the effects it could have on your credit scores. Know too, that when you're buying a car or looking around for the best mortgage rates, your inquiries may be grouped and counted as only one inquiry for the purpose of adding information to your credit report. In many commonly-used scoring models, recent inquiries have greater effect than older inquiries, and they only appear on your credit report or a maximum of 25 months.
Reducing your balances on credit cards and other revolving credit accounts is likely the better option to improve your credit utilization rate, and, subsequently, your credit scores. Consistently making on-time payments against your debt will also help you build a positive credit history, which can have additional benefits for your credit history and, by extension, your credit scores, too.